ARS | Publication request: MOLECULAR VARIATION AMONG AND WITHIN DIVERSE KENTUCKY BLUEGRASS GERMPLASM

Submitted to: Molecular Breeding of Forage and Turf Conference
Publication Type: Other
Publication Acceptance Date: January 1, 2003
Publication Date: May 1, 2003
Citation: BERTOLI, F.B., JOHNSON, R.C., KISHA, T.J., JOHNSTON, W.J. MOLECULAR VARIATION AMONG AND WITHIN DIVERSE KENTUCKY BLUEGRASS GERMPLASM. Molecular Breeding of Forage and Turf Conference. 2003. p. 141

Technical Abstract: Characterizing molecular variation in Poa pratensis L. (Kentucky bluegrass) will enhance germplasm management and utilization. Eight populations of Kentucky bluegrass from the USDA collection, and two cultivars (Kenblue and Midnight), were characterized with 115 molecular markers using AFLP analysis. The entries were selected for their diverse turf and seed production capacity based on previous research. Gels were scored for the presence or absence of specific markers and a similarity matrix developed using the simple matching coefficient. Cluster analysis and principal coordinates showed that plants within populations tended to group together, indicating that entries were distinguished using AFLP markers. Variation in similarity within entries was also observed, and differed among entries. The least diverse accession, PI 371768, had an average similarity of 0.93; the most diverse accessions, PI 539057, averaged 0.78. Kenblue and Midnight had average similarities of 0.84 and 0.90, respectively. A distance matrix based on agronomic data from the same entries and plants was correlated with the similarity matrix based on molecular data (r = -31**). Even though this explained only about 10% of the total variation, a degree of correspondence was observed between agronomic and molecular diversity. The results show that molecular variation can be assessed in Kentucky bluegrass using AFLP markers. Kentucky bluegrass, as a facultative apomict, is often assumed to have minimal variation within populations. The significant variation within populations for both molecular and agronomic factors suggests there is potential for selection within populations and cultivars for germplasm enhancement and breeding.